Method of and apparatus for making lead oxide powder



1Jam. 6, 1942. L. wooDBRlDGE v 2,269,094

METHOD OF AND APPARATUS FOR MAKING LEAD OXIDE POWDER Filed Sept. 29, 1938 ffflllflllll/,h

A /M/,fw/'a/P num/fast. y l m Jos/Wg 651/6" Moog/idg@ Patented Jan. 6, 1942 METHOD oF AND APPARATUS Fort MAKING f LEAD joxIDE POWDER.k

Joseph Lester Woodbridge, Philadelphia, Pa., asv signor to The Electric Storage Battery Company, Philadelphia, Pa., a corporation of New Jersey Application september 29, 1938,` serial No. 232,352

' s claims'. (C1. zs-'msi The objects of the present invention are to provide for the continuous manufacture o-f lead oxide powder'at'comparatively little cost and 'in increased quantity.

Another object ofthe invention is toprovide an apparatus by means of which the process can be economically` and satisfactorily practiced.

' According `to the present invention the surface of aistrp or ribbon of lead is microscopically crackedand oxidized and scaled by disturbing or working the surface while the ribbon is at a high temperatureand in the presence of air. a

- .The invention comprises the improvements-to be presentlydescribed and finally claimed.. In the following description reference willbe made to" the accompanying drawing forming part hereof and Vin which,

`Figure 1 is a transversetsectional View of apparatus and also illustrative of the process'of the present invention..` j i Figure'2 isy a transverseY sectional view taken on the line 2-2 of Figure 1.

Figure 3 is a sectionalview taken on the line 3-3 of Figure 1.

Figure 4 is a side view illustrating a modification of the apparatus, and

Figure 5 is a similar view illustrating another modification.

The process will now be described in connection with the apparatus shown in Figure 1. Parts of the apparatus are repeated and a detailed description will be given of one of the parts and in the corresponding part the exponent a will be applied to the reference letters used. I is a receptacle or chamber of generally rectangular shape and it is shown as open at the top and bottom. drums having corrugated surfaces. These drums are suitably driven and through them travels a strip or ribbon of lead 3. As shown the strip of lead or ribbon is produced by allowing a stream of molten lead from the melting pot 4 to pass out of the nozzle 5 onto a traveling belt 6 which passes around twodrums 1 and 8. The drum 'l is provided with flanges 9 to confine the'stream or ribbon of molten lead on either side until it 2 indicates a number of revolublev has congealed. A spray of water I0 is directed onto the lead as it leaves the nozzle 5 to cause quick solidication. The strip or ribbon of lead 3 passes through the opening II into the receptacle I and thence downwardly betweenthe various drums 2 at the left-hand side of the chamber I then across horizontally and upward around the various drums 2 on the right-hand side of the chamber I andl out of the chamber through the opening I2.' FromY that point the strip of lead passes through the opening IIa, of the second chamber Iaand finally' the strip or ribbon passes out of the second chamber through the opening I2a from which point it passes into the melting pot I3; The lead in the melting pot I3 may bey returned to the meltingpot 4.V

The .strip of. lead'3 is `guided around the drums l2 by stationary guides I4. Theseguides are made of members spaced apart to permit fine powder which' is detached; from the lead ribbon to sift downwardto the bottom of the chamber I where it is discharged through a hopper like opening into ay suitable 'drum'or receptacle I5. The Stationary guide I4 is located beneath the horizontal portion of the lead strip or ribbon 3 and curves aroundv the two bottom drumsv as shown. The guide I6v is of generally triangular form as shown in Figure 3 in order to shed powder settling down upon :.it so that the powder will fall into the druml.' v"A supply' of air 'which may-be heated is. furnished by meansv of ja blower25 `equipped withlaheater I8.. The air is supplied throughl the'xvertical'pipe I'Ij in'which openingsareprovided opposite the stationary guides I4. Thus streams of heated air are directed upon the lead strip or ribbon.

As the lead strip passes through the apparatus its surface becomes oxidized and the fine oxidized particles are detached falling tothe bottom of the chamber and into the receiving drum. The lead strip becomes attenuated but before it becomes sol thin as to endanger its breaking into pieces of comparatively large size and while it is still in the form of a continuous ribbon it passes yout of the final opening |201.l in the last` chamber and into the melting pot I3. In the modification shown in Figure 4 the lead ribbon 3b is conducted upon a conveyor 26 beneath rolls I9 which work its surface and past air injectors 20. led past hammers or hammering devices 2| and over rolls 22. In the form of apparatus illustrated in Figures 4 and 5 the lead powder is delivered at the right-hand end. Referring to Figure 4, 23 indicates a device for controlling the flow of molten lead from the receptacle 24.

The principle, involved is that when the surface of a piece of lead is deformed as by bending,

crushing or otherwise the crystalline structure' is broken up by the formation of inter-crystalline seams or creviees of microscopic dimensions. If this deformation occurs at elevated temperature and in the presence of air the intercrystalline surface thus exposed will become oxidized and As shown in Figure 5 the lead ribbon 3c is this lm of oxide will prevent any subsequent rewelding or reunion of the surfaces so that the fractures become permanent. If this process of deformation is repeated these inter-crystalline fractures will finally result in the detachment of fine particles of oxidized lead.

It may be remarked that 21 indicates gas burners adapted to supply heat to the lead tape or ribbon.

It will be obvious to those skilled in the art that modifications may be made in details of construction and procedure without departing from the spirit of the invention which is not limited to such matters or otherwise than the prior art and the appended claims may require.

I claim:

1. A method of making lead oxide powder from a long integral ribbon of metallicr lead which consists in moving the ribbon endwise, progressively and repeatedly disturbing the structure at the surface of the ribbon while at elevated temperature and in the presence of air and detaching fine particles of oxidizedlead.

2. A method of making lead oxide powder which consists in deforming the structure at the surface of an endwise traveling, long integral lead ribbon by mechanically working the ribbon in the presence of air and at high temperature.

3. A method of making lead oxide powder from a long integral ribbon of metallic lead which consists in traveling the ribbon endwise and forming a film of oxide on the surface of the ribbon and scaling the ribbon by progressively and repeatedly mechanically disturbing its surface while at a high temperature and in the presence of air.

4. A method of making lead oxide powder from an endwise traveling ribbon of metallic lead which consists in microscopically cracking and oxidizing and scaling the surface of the lead ribbon by disturbing the surface of the lead ribbon at spaced intervals along its path While it is at a high temperature and in the presence of air.

5. A method of making lead oxide powder which consists in deforming the structure at the surface of a lead ribbon by alternately flexing and refiexing the ribbon in the presence of air and at elevated temperature.

6. A process for manufacturing lead oxide by continuously feeding a long, integral lead ribbon endwise, and disturbing the surface structure of the ribbon as by bending the ribbon back and forth in the presence of an oxidizing atmosphere.

7. A process for manufacturing lead oxide by continuously feeding a lead ribbon endwise and disturbing the surface structure of the ribbon by hammering the ribbon with a hammer in the presence of air and at an elevated temperature.

8. Apparatus for making a powdered oxide from an oxidizable material comprising, a stationary casing having inlet and outlet ports therein adapted to closely t and restrict the escape of gas from around a long integral ribbon of said material passing through said ports, mechanical parts of said apparatus mounted in said casing and arranged to disturb the surface of said ribbon and to remove from the surface of said ribbon the powdered oxide so formed, and conduits for supplying an oxidizing atmosphere to said ribbon in said casing.

9. Apparatus for making a powdered oxide from an oxidizable material comprising, a stationary casing having inlet and outlet ports therein arranged to closely t and to restrict the escape of gas from around a long integral ribbon of said material passing through said ports and having an outlet port for the escape of powdered oxide from said casing by gravity, mechanical parts of said apparatus in said casing and arranged to convey and support said ribbon through said casing and to disturb the surface of said ribbon and to remove from the surface of said ribbon the powdered oxide so formed, and a conduit for introducing oxidizing atmosphere into said casing and onto said ribbon in said casing.

JOSEPH LESTER WOODBRIDGE. 

